This proposal addresses a fundamental topic relative to Complementary and Alternative Medicine (CAM) treatments: How do we measure the context of an encounter? Encounters are defined as what patients experience between when they arrive at a CAM practice site and when they leave. The encounter can be divided into two parts: (a) the experience of the main treatment intervention (the intervention) and (b) all other experiences before, during, and after the intervention itself (the context). Contextual effects play two critical roles in assessing the efficacy and effectiveness of CAM interventions. First, contextual effects may mediate how well a treatment works (context as mediator). Second, context effects may actually contribute to outcomes directly (context-as-intervention). In a classic RCT, investigators typically want to control for context-as-mediator effects and measure context-as-intervention effects to disentangle what portion of the results are due to the intervention and what are due to the context. In CER, investigators are less concerned about controlling for context-as-mediator effects, but they would like to understand what part of the encounter accounts for any positive results. In either case, investigators MUST know how to measure the context. Without such measures, it is impossible to assess either type of context effect. This proposal has 3 specific aims: 1. to understand what kinds of contextual factors patients are exposed to during CAM encounters? 2. To determine how to measure such contextual factors reliably via observation and/or patient and provider recall;and 3. To assess the degree to which contextual factors might vary within and across (a) CAM modalities (i.e., chiropractic versus osteopath);(b) practice sites, (c) providers, and (d) individual patient encounters This study will use the chiropractic encounter as an exemplar for CAM and develop a rapid ethnographic observation method to study the context of the encounter. The objective of this project is to develop a reliable, valid, and rigorous methodology for collecting data about the context. The proposed study addresses a fundamental issue of all outcome studies in health: how to measure the effect of the context on the health outcomes. PUBLIC HEALTH RELEVANCE: A fundamental issue in evaluating complementary and alternative medicine (CAM) interventions is how to measure the effect of the context of an encounter and its contribution to the outcomes. The aim of the proposed study is to develop a rapid ethnographic observation method, using the chiropractic encounter as an exemplar of CAM, to study the context of an encounter.